Recursively remove json keys in an array

stripJSON.js

/**
 * @function stripJSON
 * @desc - This function removes selected object keys
 * @param {Object} json - JavaScript object to strip
 * @param {Object[]} keys - array of selected keys (string)
 * @return {Object} - deep copy of object without keys
 */
function stripJSON(json, keys) {
  if (json === null || json === undefined) return json;
  let obj = {}, key;
  for (key in json) {
    let inside = keys.indexOf(key);
    if (inside !== -1) continue;
    
    if (typeof json[key] === 'object') {
      obj[key] = stripJSON(json[key], keys);
    } else {
      obj[key] = json[key];
    }
  }
  return obj;
}